The recent Space Shuttle tragedy has refocused
our minds on the perils of space travel. In this article we take
a broader look at the history of space disasters over the last four
decades.

by Stuart Carter

Space is an airless
vacuum of burning heat and searing cold. It’s the most hostile
environment imaginable. Yet reaching out into this lifeless void
is man’s ultimate dream – and the ultimate challenge.
We have been redefining our place in the universe since 1961. We
have broken the bonds of gravity and we have walked on the moon.

But conquering the
final frontier often comes at a price. January 1997:Russia’s
MIR space station was setting records as the only continuously occupied
man-made structure in space. It had been in orbit for 11 years when
American astronaut Jerry Linenger joined the crew. During the crew
exchange, the space station’s compliment doubled from three
to six. MIR’s aging oxygen generators were pushed to their
limits. A simple spark became a raging fire. Linenger: “All
of a sudden I heard the master alarm. The fire was blasting across
the entire module. Fire was shooting this way, molten metal flying
this way, getting splattered on the far bulkhead, sparks flying
and smoke billowing out.”

The smoke was acrid
and incredibly dense. The crew’s first priority was the desperate
search for breathable air. “I grabbed the oxygen mask. Activated
it. Got nothing. At this point I felt like I had been swimming under
water for maybe 25 metres and needing air. Grabbed the second oxygen
mask, put it on, sort of kept my fingers crossed, said a quick prayer
and I got oxygen.” It took 14 minutes before Linenger and
Tsibliev finally got the situation under control.

Official
portrait of Astronaut Jerry M. Linenger
as taken in 1992

America’s worst
fire didn’t happen in space but here on Earth on a launch
pad on Friday January 27, 1967.This was supposed to have been a
run through of America’s first Apollo capsule. Instead Apollo
1 claimed the lives of astronauts: Gus Grissom, Ed White and Roger
Chaffee. Six hours into their exercise, a spark from faulty wiring
ignited the capsule’s pure oxygen environment, instantly turning
the spacecraft into a furnace. After the Apollo 1 tragedy, NASA
replaced the 100% oxygen atmosphere with a safer, non-flammable
mixture of oxygen and nitrogen.

For shuttle crews,
the eight-minute ride to orbit is intensely dangerous. While the
solid rocket boosters, the SRBs, are firing, stresses on the vehicle
make it impossible for the crew to escape. The spacecraft’s
three main engines burn liquid fuel at a ton every second. The SRBs,
are the workhorses of the system, blasting shuttles into orbit since
the early 1980s. SRB’s are 450 tons of pre-packed high explosive.
Once lit an SRB can’t be turned off.

On an unseasonably
cold day in January 1986 an enthusiastic shuttle crew began their
trip to the launch pad. Although shuttle launches had become routine,
a shuttle had never been flown in such cold conditions. Ignition
was perfect, lift-off flawless. 2,000 tons of hardware accelerated
through a clear blue sky towards 25 times the speed of sound. But
a tiny leak from a frozen rubber ‘O’ ring seal on one
of the SRBs was allowing burning gas to escape and melt a supporting
strut. The strut gave way --- and the booster hit the external tank
containing half a million gallons of liquid hydrogen. Challenger’s
10th flight was to be her last.

When a shuttle does
finally take off, it is protected by millions of safety systems.
And sometimes these systems abort the launch with just seconds to
lift off. Once the SRBs are jettisoned, there’s still the
chance of a main engine malfunction. At this stage the three main
engines are still burning propellant at over 1,000 gallons a second.
For a human working in the vacuum of space, personal protection
is vital. Each space suit is in reality a miniature spacecraft.
As the numbers of men and women living and working in space grow,
so will the numbers of space walks. But a space walk is not to be
taken lightly - space is quite simply the most inhospitable environment
any living creature could possibly face. Linenger: “You open
that door without a space suit on and essentially you will come
apart.”

Challenger
wreckage remains and boxes of debris being lowered into
abandoned Minuteman Missile Silos at Complex 31 on Cape
Canveral Air Force Station.

A tear big enough to
expose you to the full vacuum of space would be one of the most
painful deaths imaginable. All the air would be sucked from your
lungs. Blood would feel as if it was boiling in your veins, and
your internal organs would go into seizure. A space walker must
keep tethered to his spacecraft. There are no second chances...

But perhaps those astronauts
who dared leave the relative safety of Earth orbit took the greatest
risks of all. On April 20th 1972, Charlie Duke became one of only
12 human beings to ever set foot on a world outside our own. “The
lunar surface was to me incredibly beautiful – lifeless, hazardous,
it was the most desert you could ever imagine and yet you felt right
at home. It’s hostile, I mean there’s no atmosphere
up there, you depend on that suit. If the zipper splits open you’re
dead. If a glove pops off you’re dead…”

In its quest for the
moon NASA’s Apollo program proved man could reach for other
worlds. But long-duration missions are still a major challenge.
Russia’s MIR space station was suspended in Earth orbit for
15 years - a fragile bubble of life in the vacuum of space. It had
already suffered a major fire but worse was still to come.

In May 1997, the next
NASA astronaut (person) to step on board MIR was British born Michael
Foale. Foale’s Russian crewmates Vasiliy Tsibliev and Sasha
Lazutkin, had already served a total of six months aboard MIR. Little
did these three men know that they were about to endure the worst
on-orbit collision accident in space history. Just like Linenger
before him, Foale was surprised by the conditions he found on board
the space station. Much of this clutter was waste that had to be
stowed until it could be disposed of on regular visits by ‘Progress’,
MIR’s unmanned supply ship. The radar system used to pilot
‘Progress’ from the ground was expensive. To save money
a cash strapped Russian mission control decided the crew on board
MIR should guide ‘Progress’ in manually. This near impossible
task fell on the shoulders of MIR’s commander - Vasiliy Tsibliev.

Tsibliev was expected
to manually dock two spacecraft traveling at 18,000 miles an hour.
Tsibliev’s only visual aid was a single, low-resolution video
camera mounted on ‘Progress’ itself. To help their commander
judge the distance of the approaching spacecraft, Foale and Lazutkin
took turns shouting instructions from portholes around the space
station. It was an impossible task. As ‘Progress’ closed
Tsibliev lost control. 7 tons of hurtling spacecraft - the size
of a small bus - collided with MIR’s ‘Spektr’
module...

The MIR
Space Station

The impact ruptured
the ‘Spektr’ module. The hiss of escaping air rushed
through MIR. The space station tumbled out of control. Foale rushed
through the station. It was a race to seal the hatch that led to
the crippled module and contain the leak before all of MIR de-pressurized.

17 minutes after the
impact, they managed to seal the hatch. MIR was tumbling out of
control, its solar panels damaged and no longer pointing at the
sun. With no power the crew worked in dark, dead silence for 14
hours. Finally the crew managed to stabilize the space station and
regain control.

Having helped avert
a major catastrophe Foale was safely returned to Earth on NASA’s
space shuttle. But bad luck continued to plague the exhausted Tsibliev
and Lazutkin on their return to Earth. The retro rockets designed
to fire and cushion their capsule’s hard landing malfunctioned.
Lazutkin injured his back, and Tsibliev was about to become a political
scapegoat. The ageing space station limped on for a few more years.
MIR finally tumbled back to Earth and crashed in to the pacific
in March 2001.

Re-entering the Earth’s
atmosphere is no mean feat. Most objects that fall through the atmosphere
such as small asteroids or space debris never make it at all. They
burn up by friction when they collide with the atmosphere 60 miles
above the surface.

Once the astronauts
fire their retro rockets, you drop into the Earth’s atmosphere.
There is no turning back. Traveling at 5 miles a second - that’s
18,000 mph - the early Mercury astronauts were reaching into the
unknown. There was no margin for error - the angle at which they
hit the planet’s atmosphere was the most critical part of
the whole journey. And when a capsule starts to re-enter the Earth’s
atmosphere, the crew are on their own...The capsules were engulfed
in a huge fireball and during that time no one could talk to them
from the ground. In fact the most dangerous part of the Mercury
capsule’s journey was not re-entry but splashdown. In 1961,
6 years before he died in the Apollo 1 accident, Gus Grissom nearly
drowned when his hatch blew open on splashdown. He was saved by
the waiting rescue services, but his Mercury capsule sank thousands
of feet to the bottom of the Atlantic Ocean.

For cosmonauts, capsule re-entry is still their only way home. But
touchdown on land rather than water can be lethal. In 1967, a Soyuz
capsule pile drived into the ground. It’s lone occupant, cosmonaut
Vladimir Komorov made it through the perils of launch and orbit,
only to die because of a faulty parachute.

To make re-entry as
safe as humanly possible, NASA designed the Space Shuttle, with
many new, groundbreaking technologies. They equipped the outer skin
with a lightweight, re-usable heat shield that would protect both
vehicle and crew. These Thermal tiles are so heat insulating that
even at 1, 300 degrees centigrade, they can be picked up with your
bare hand. Each shuttle has a total of 25,000 tiles on its outer
surfaces. The shuttle begins its descent at a staggering 5 miles
a second. To slow down it performs a series of ‘S’ shape
turns that create extra drag - the tiles becoming hotter than a
blast furnace as the shuttle smashes through the atmosphere.

A shuttle can lose
one or two thermal tiles and survive, but if a whole section broke
free...

We may never know what
caused the break up of the Columbia Shuttle. Whatever the cause
it seems almost certain now that the thermal insulation layer was
insufficient to counter the heat. Did something damage the tiles
on lift off? Was there a computer malfunction? It may take NASA
years to know. One thing is almost for sure the Shuttle will have
to fly again; if only to provide proper support to the three astronauts
left stranded on the ISS. But its days are surely limited. In just
over 100 flight two orbiters have been lost.

When the next shuttle
launch does take place it will be under incredible scrutiny as it
appears over the skies of Florida. At this point of its journey
the Shuttle is an unpowered glider and the commander will have just
one shot to hit the runway.

Each completed mission
challenges us to take the next step forward. Humans are an adventurous
species, facing the unknown, is nothing new. No-one knows what other
dangers will confront the men and women who venture into space but
one thing is certain, their stories will inspire a whole new generation
to explore the final frontier.

Click
Here for a follow up article to this one,
Men
in Space? Where Sir Martin Rees reflects on the recent space
tragedy, and ponders the question of the dangers of men travelling
into space.